Systems and methods for deflecting the electron beam of a cathode ray tube are well known in the art. Such known systems and methods, however, commonly require that flyback, or retrace, occur after each scan line.
As cathode ray tube displays have become more refined, it has been necessary that higher and higher frequencies of line rates be utilized, and such high frequency line rates have proved to be difficult to implement because of the increasing amount of power that must be dissipated in the deflection system component, a significant amount of which occurs during flyback, or retrace. It is therefore obvious that elimination of flyback, or retrace, would enhance such displays.
Bidirectional line scanning of cathode ray tube displays has been heretofore suggested, but such scanning has heretofore required that the camera supplying the video information to the cathode ray tube for display also utilize bidirectional line scanning (see, for example, U.S. Pat. No. 3,662,102 showing bidirectional horizontal line scanning. and U.S Pat. Nos. 2,717,329 and 2,817,787 showing bidirectional angular line scanning). Such systems, however, are not able to accept conventional video information and display the same utilizing bidirectional scanning without loss of intelligibility.
Memory storage by scan lines has also been heretofore suggested for use in conjunction with a display (see, for example U.S. Pat. Nos. 4,205,310 and 4,203,102), but such suggested devices have been utilized for specialized purposes and not for bidirectional scanning of alternate lines of a cathode ray tube display.